By introducing a control plane between a transport plane and a management plane of a conventional optical network, an Automatically Switched Optical Network (ASON) has automatic neighbor, automatic link and automatic topology discovery functions, combines a rerouting mechanism for the control plane with protection mechanisms such as subnetwork connection protection and multiplex section protection of the conventional optical network, and can flexibly and automatically provide various protection and restoration services, such as permanent 1+1 protection, 1+1 protection plus restoration, multiplex section protection plus restoration, shared MESH restoration, dynamic restoration, no protection, and extra service.
To effectively recover a service when a failure occurs, the prior art provides the following technical solutions:
A first technical solution: ring network protection technologies such as multiplex section protection in a Synchronous Digital Hierarchy (SDH) network or shared protection ring in an Optical Transport Networks (OTN) network are adopted to protect multiple services simultaneously interrupted by network failures, and service protection switching time can be controlled within 50 ms. However, a drawback of the solution is in that, bandwidth resource usage rate of the network is low, and network topology planning is complex.
A second technical solution: a shared MESH recovery solution is adopted. The solution can share recovery resources, and increase the resource usage rate. However, a drawback of the solution is in that, when a link fails, the affected services individually and independently initiate rerouting signaling, and the process for signaling transmission and processing occupies the communication bandwidth and processing time of a system, so that recovery time delay occurs, and service requirements of customers cannot be satisfied.
During the development of the present invention, the inventor finds that the prior art at least has the following problems:
Although the recovery time of a service adopting the conventional multiplex section protection mechanism is short, the average resource usage rate is low and network planning is complex. Although a method adopting the shared MESH recovery mechanism can increase the resource usage rate, the service recovery time of the method is longer than that of the conventional multiplex section protection mechanism, and the service requirements of customers cannot be satisfied.